Role Reversal: Clippers and Lakers

This is the 43rd NBA Season for the Los Angeles Clippers.  Over the first 42 years of their existence (in Los Angeles, San Diego and Buffalo) they won 36.7% of their games.  They had a winning record in only 7 of their first 42 seasons and have never won more than 50 games in a single season.  Their typical season has been 30 wins and 52 losses.  This year’s team has the best record in the NBA and has won 28 of their first 36 games.  The Clippers of old, with a 36.7% winning percentage, would be expected to start the season this well once in every 1.65 million seasons.

The Los Angeles Lakers have been playing in the NBA for 65 seasons (including Minneapolis).  They won 62% of their games in their first 64 seasons and had a losing record in only 12 of those seasons.  The typical Laker team has a record of 51 wins and 31 losses.  In fact, the Lakers have won at least 50 games in 32 different seasons.  This year’s team has won only 15 of their first 35 games and is in danger of missing the playoffs.  The Lakers of old, with a 62% winning percentage, would be expected to get off to that poor of start once in every 60 seasons.

The NBA Players’ Association Should Support Greg Popovich’s Decision to Rest Players

David Stern, commissioner of the NBA, fined the San Antonio Spurs $250,000 for resting four starting players, including stars Tim Duncan, Manu Ginobli and Tony Parker, in their game against the Heat in Miami on Thursday November 29.  The Spurs barely lost to the defending champion Heat in the closing minutes despite the fact that they played without four of their top players.  Coach Greg Popovich’s strategy may have worked, however, as the Spurs defeated the Memphis Grizzlies in overtime on Saturday night.  Memphis had the league’s best record entering the game.  Duncan, Ginobli, and Parker require more rest than many NBA stars because their ages are 36, 35 and 30, respectively.

Coach Popovich rested his top players because the Spurs were playing their third game in four nights and were in the midst of playing six games in nine days.  Teams playing three games in four nights tend to be fatigued and win fewer of the back-to-back games at the end of these sequences of games.  Most of the games played at the end of these sequences tend to be on the road, where the fatigued team is also the visiting team.  I analyzed NBA schedule data from the 2010-2011 season because the 2011-2012 season was strike-shortened and had a compressed schedule.  My analysis focused on away teams because of the small sample of home teams playing with such little rest in between games.  I found that NBA teams are significantly less likely to win a game when they are fatigued.

  • Visiting teams won 41% of NBA games when playing with at least one night’s rest (and not in the midst of three games in four nights).
  • Visiting teams won less than 29% of NBA games when playing back-to-back games at the end of a sequence of three games in four nights.

Playing games without much rest puts NBA teams at a disadvantage.  Rather than fining Greg Popovich for optimizing given the schedule the NBA has dictated to the Spurs, perhaps David Stern should be more concerned about scheduling equity.  Seven of 30 NBA teams (Cleveland, Golden State, Los Angeles Clippers, Milwaukee, Minnesota, New York and Washington) have to play three games in four nights on four different occasions this season.  Six teams (Boston, Dallas, Los Angeles Lakers, Memphis, Orlando and Utah) are scheduled to play three games in four nights at most once during the season.  The Spurs are scheduled to play three games in four nights on three occasions and therefore have one of the NBA’s least advantageous schedules in terms of opportunities for resting players.

It is not clear whether the Spurs will appeal Commissioner Stern’s fine.  If the Spurs appeal, the NBA Players’ Association should support their challenge.  First, resting players makes sense because it maximizes a team’s chance of success in a league where fewer than half of the teams are eliminated from the playoffs over the course of an 82 game schedule.  Second, resting players is likely to reduce the risk of serious injury.  As representatives of the players’ welfare, the NBA Players’ Association should be challenging the Commissioner’s decision.

Impatient Lakers and Patient Spurs

Mike Brown was relieved of his coaching duties by the Los Angeles Lakers because the team was playing poorly and underperforming during the first 6% of the 2012-2013 season.  Brown had coached the Lakers for one season prior to winning just one of the team’s first five games this year.  Brown’s boss General Manager Mitch Kupchak said:

The bottom line is that the team was not winning at the pace that we expected this team to win and we didn’t see improvement.  After five games, we just felt that we weren’t winning.  We made a decision. Maybe it would have changed a month or three months down the road, but with this team we didn’t want to wait three months and then find out it wasn’t going to change.

The Lakers have high expectations after acquiring veterans Dwight Howard and Steve Nash and want to win immediately with aging superstar Kobe Bryant.  The Lakers also have an unmatched history of achievement in professional sports having appeared in 47% (31 of 66) of all the NBA Finals ever held.  In addition Los Angeles is a city without an NFL franchise so the Lakers are the hottest ticket in town.  If this year’s team doesn’t win millions of fans will blame the failure on poor management and coaching.  It is not surprising that the Buss family, which owns the Lakers, is impatient.

As it turns out almost all NBA teams are impatient with their coaches even when compared to other sports.  The median and mean years of tenure of head coaches in the NBA, the NFL and Division I college basketball coaches heading in to the seasons this fall are:

  • NBA: median tenure is 2 years and mean tenure is 2.61 years
  • NFL: median tenure is 3 years and mean tenure is 4.09 years
  • NCAA Division I Basketball: median tenure is 3 years and mean tenure is 5.03 years

 The tenure distribution is highly skewed because of San Antonio coach Greg Popovich who has coached the Spurs for over 15 seasons.  Without Popovich, whose coaching tenure is 6.7 standard deviations above the average for the rest of the NBA, mean coaching tenure would be only 2.14 years.   Put somewhat differently, Popovich alone is responsible for 20% of all of the head coaching experience (with their current team) among NBA coaches.  The comparison between the Spurs and Lakers is important because each team has brought in different groups of veteran players to fit in with a core of superstars who remain from one season to the next.  In some seasons it takes longer for the new veteran players to fit in with the team.  It is hard to imagine that Spurs owner Peter Holt or the team’s fans would panic if the team started a season with only one win in its first five games.

Most professional sports team owners are impatient.  Head coaches tend to have less time to achieve success than management in less visible organizations.  The median tenure in management occupations in the U.S. is 6.3 years, but few professional team owners would give a coaching staff six seasons to achieve success.  It is not clear, however, that changing coaches is the most effective way to maintain excellence.  The Lakers have made 11 coaching changes in the 22 years since Pat Riley left as head coach, once every two years (about the NBA average).  The small market Spurs have not changed coaches since 1996 after making twelve changes over the previous two decades.  In the NFL the small market Pittsburgh Steelers have won consistently with three coaches in the past 43 years.

Coaches are on the hot seat more in larger markets where owners have paid millions of dollars for high-priced athletes whose careers are relatively short.  The owners of franchises in San Antonio and Pittsburgh make fewer coaching changes than owners in New York and Los Angeles.  Nonetheless, Mike Brown’s firing after coaching five games with many newly acquired players sets a new standard for impatience in the NBA.

The Most Dominant Basketball Team in Olympic History

As the US men’s basketball team heads to London for the 2012 Summer Olympics, many have speculated about how this year’s team would match up with the 1992 Dream Team.  There is no doubt that the 1992 team, with Michael Jordan, Magic Johnson, and Larry Bird was the most talented team in Olympic history.  Every player on the 1992 team, other than Christian Laettner, is a member of the Basketball Hall of Fame. 

The Dream Team was not the most dominant team in Olympic basketball history.  The 1956 team, with Bill Russell and K.C. Jones (from the University of San Francisco) scored 773 points in eight games while allowing only 365 points.  For each one point scored by their opponent, the US team scored 2.12 points, a record for Olympic games in which basketball was played indoors (since 1948).  The 1992 Dream Team faced tougher competition and scored 1.6 points per point allowed, sixth best in modern Olympic basketball history.  The most under-achieving US team in Olympic history is the 2004 team that won the Bronze medal but lost three games.  The 2004 team only scored 1.05 points per point allowed.

The 1956 summer games were played in Melbourne in November and December.  Bill Russell, the team’s captain and biggest star, delayed the beginning of his pro career with the Boston Celtics to play in the Olympics.  Russell was one of the world’s top high jumpers and probably could have competed on the U.S. track team.  He went on to win 11 NBA titles in his 13 year professional career and is considered the greatest defensive player in basketball history.

The NBA’s Small Market Ratings Problem

NBA Commissioner David Stern breathed a sigh of relief last night when the Miami Heat took charge in the fifth game of their playoff series with the Indiana Pacers.  The NBA already faces a ratings challenge in the Western Conference with the small market Oklahoma City Thunder and San Antonio Spurs.  After a protracted strike that shortened the season, compressed the schedule, and lowered the quality of play, the Association was hoping for a more appealing Finals match-up than they are likely to get.  The Thunder and Spurs are clearly the best teams in the West; the problem is they don’t have many fans.  An NBA Finals matchup against the Indiana Pacers would have produced historically low ratings.

Oklahoma City and San Antonio are the third and fourth smallest television markets in the Western Conference.  Only Memphis and New Orleans have smaller markets.  Before the season began there were 105 possible Western Conference Finals matchups, and 98 have larger combined markets than Spurs-Thunder.  There are fewer television households in Oklahoma City and San Antonio combined than there are in Minneapolis, alone.  The combined size of the television market for the Spurs and Thunder is 52% smaller than the median matchup (Minnesota Timberwolves – Denver Nuggets) and 81% less than the best matchup of the Lakers (or Clippers) and Dallas Mavericks.

The ratings of NBA Finals are directly related to the market size of the participating teams.  There have been 13 NBA Finals played since Michael Jordan left the Chicago Bulls.  The Spurs have played (and won) in four and the Los Angeles Lakers have played in seven of the Finals.  The ratings are 24% lower when the Spurs are in the Finals compared to the Lakers.

The challenges of a Spurs-Thunder matchup would have been compounded by an Indiana Pacers win last night.  Indianapolis is the sixth smallest market in the NBA and only Milwaukee is smaller in the Eastern Conference.  There has not been an NBA Finals from smaller markets than Oklahoma City and Indianapolis since the Fort Wayne Pistons played the Syracuse Nationals in 1955.  Conspiracy theorists were probably silenced last night because the game wasn’t close.  Nonetheless, the NBA and ABC, the network televising the Finals, are hoping that the midsize market Miami Heat (with considerable star power) or large market Celtics or 76ers prevail in the East.  Regardless of the Eastern Conference winner, however, the ratings for the NBA Finals are likely to be the lowest in history edging out the 2007 matchup between the Spurs and Lebron James’ Cleveland Cavaliers.

The Costs of Labor Unrest and the NBA’s Compressed Schedule

The NBA has twice attempted to fit more games into a compressed time period in a strike-shortened season so that fewer regular season games (and less revenue) would be missed.  This year the NBA squeezed 66 games into a regular-season schedule between Christmas and the last week of April.  The lack of rest days led to greater player fatigue, less efficient scoring and possibly more injuries.  The season-ending injury to reigning MVP Derrick Rose over the weekend has raised questions about the wisdom of a compressed schedule.  NBA coaches tried to mitigate the impact of the compressed schedule by resting their star players more this season.  The best NBA players sat out 5% more of regular-season games than in 2010-2011 and 11% more than a decade ago.  The league’s labor strife led to lower quality play, less participation by NBA superstars, and may have increased the risk of injuries.  Next time there is a strike or lockout the NBA and its Players’ Association should be honest with their fans, and either reach an agreement sooner, or compress the schedule far less than they have in the past.

In an earlier post I illustrated that shooting percentages in the NBA are lower in strike-shortened seasons.  Effective shooting percentages in the NBA have been fairly stable since the three point shot was introduced in the 1979-1980 season.  Ignoring strike-impacted seasons more than 75% of the year-to-year changes in shooting percentage have been between -0.6% and +0.6%.  In contrast, shooting percentages declined by 1.1%, on average, during the two strike-shortened seasons in the past 14 seasons.

The next chart shows that the number of minutes played by the 50 top scoring NBA players has been trending down for more than a decade.  A decade ago the top 50 scorers played the equivalent of just less than 61 complete games (48 minutes in length) over the course of a season.  By 2010-2011 the number of minutes played fell to the equivalent of 56.7 full-time games (a decline of about 6.5%).  In the just completed strike-shortened season, the number of minutes played fell by 5% in just one year.  After extrapolating minutes played to the usual regular-season schedule, this means that this season top players were on pace to play the equivalent of 53.8 complete games over an 82 game schedule.

Top scoring players have been sitting out more minutes and more games in recent years compared to a decade ago.  This may be because benches are deeper or that coaches are resting their players more for the playoffs than they did just 10 years ago.  Even after accounting for the declining trend in minutes played by NBA stars, the strike reduced the participation of top players by 5% (the equivalent of three 48 minute games).  Whether one looks at minutes played by stars or shooting percentages there is little question that the quality of play in the NBA in 2011-2012 was diminished by the lockout.

The NBA and its Players’ Association could have mitigated the deterioration in the quality of their product by reaching an agreement a week or two before their 11th hour deal last December, or by scheduling fewer games and a few more off-days in their already-shortened season.  Strikes and lockouts are costly because of the revenue foregone by management and the union.  NBA management and players tried to shift some of these costs to fans by providing lower quality entertainment in a compressed schedule instead of playing fewer games and charging fans less.

Why Does David Stern Think Defense is Boring?

Real sports fans appreciate excellent defense.  Nonetheless, commissioners of professional sports leagues seem to think that fans are bored by defense.  David Stern of the NBA typifies this mindset.  The NBA All-Star Weekend is a showcase for its stars and it’s all about offense.  I understand that the All-Star game is an exhibition not a competition, but whatever they played last night in Orlando looked nothing like professional basketball.

David Stern, who became Commissioner in 1984, has used the All-Star weekend to market the NBA.  A big change was the introduction of the slam dunk contest in 1984.  The dunk contest used to feature basketball’s biggest stars making shots that could conceivably occur in game situations.  The contest no longer attracts stars and now features dunks over props such as cars and motorcycles.

All-Stars in the exhibition game play as much defense as the props in the slam dunk contest, but that wasn’t always the case.  Before 1984 the average score in an All-Star game was about 20 points or just 9 percent higher than in an average regular season game.  Since 1984 the total point differential between the All-Star game and the regular season has steadily increased by 1.6 points per year.  Over the past 6 years the average All-Star score was 83 points higher (42 percent) than in the regular season.  Last night’s game produced 111 more points (58 percent) than we have seen this season.

The dunk contest and the All-Star game have become caricatures of the sport of basketball.  I wish the NBA would give basketball fans more credit and recognize that we appreciate all aspects of the game – including defense.

NBA Players Can’t Shoot Straight after the Lockout

All the excitement generated by Jeremy Lin seems to have distracted fans from what’s really happening this NBA season.  Charles Barkley is paying attention, and he said “As a NBA fan, I want to apologize to the fans.  I cannot believe how bad the NBA is right now.” Offenses are performing poorly this season and there is a simple explanation, the lockout that delayed the start of the season and all but eliminated team practices.

This is the second NBA lockout serious enough to result in limited training camps and a shortened regular season; in 1999 the NBA played a 50-game schedule.  NBA lockouts reduce shooting accuracy and these negative effects may persist for several seasons.  Basketball productivity probably declined because pre-season practices, mid-season practices and rests days were curtailed in order to fit 66 games between Christmas and late April.

The following figure illustrates the average effective shooting percentage in NBA regular seasons from 1980, when the 3 point shot was introduced, to the current season (so fare).  The effective shooting percentage is a weighted average of 2 point and 3 point shooting percentages, where each 3 point shot receives one and a half the weight of a 2 point shot.  The figure indicates that although shooting accuracy varies from year to year, it dropped shortly after both work stoppages, and remained lower for several seasons after the 1999 lockout.

I estimated a simple regression that allows for differences in shooting accuracy among teams and correlation in the fluctuations in a team’s shooting percentage from one year to the next.  The regression model suggests that lockouts cause a 1.5% decline in the effective shooting percentage in the first season after a lockout.  The model also predicts that shooting percentages will remain lower because of the time series correlation in shooting accuracy.

The statistical model can be used to predict how the most recent lockout will reduce NBA scoring over the next few seasons.   Combined scoring by both teams is expected to drop by 5.5 points in 2012 and 3.3 points in 2013 due to the reduction in shooting accuracy.

NBA coaches and teams can adjust strategies to mitigate the impact of the prolonged lockout.  For example teams can attempt more (or fewer) 3 point shots and slow down (or speed up) the pace of play.  If these adjustments are made scoring reductions could be somewhat smaller than the model’s predictions.

Some fans believe that the NBA’s 82-game regular season is too long, so that a silver lining of the 2011 lockout is a shortened 66-game schedule.  Whether or not the regular season is too long, compressing a 66 game season into four months has a negative impact on offensive efficiency.  Practices and rest days are important, even for the world’s best athletes competing at the highest level.  The elimination of rest days and practices appears to be relatively more important for basketball offenses.

Linsanity: Why the NBA Eastern Conference needs Jeremy Lin

Jeremy Lin, New York Knicks point guard and Harvard economics graduate, has become an overnight sensation.  He has averaged almost 27 points and 8 assists per game over the past five Knicks games(all wins), including 38 against Kobe and the Lakers last Friday night.  It may sound strange but the Eastern Conference, home of LeBron James and reigning MVP Derrick Rose, needs Lin, who Magic Johnson compared to Steve Nash and John Stockton.

Magic Johnson and Steve Nash are arguably the NBA’s two best point guards in the past 35 years and they played in the West.  Outstanding point guards raise their team’s offensive efficiency by creating better shot opportunities and increasing shooting percentages.   Magic’s Lakers led the NBA in effective shooting percentage six times in the 1980s and never ranked lower than third in the league.  Nash’s Suns led the NBA in shooting for six straight seasons from 2005 to 2010 until Tony Parker’s Spurs led the league in 2011 (four of the top five teams last year were from the West).

Over the past 32 years the average Western Conference team generated 0.8 more assists per game, made 1/2 of one percent more of their shots, had 1.3 more possessions and scored 2.4 more points per game than their Eastern Conference rivals.  (All of these differences are statistically significant with probability values less than .00001).  The Western Conference has been the home of more efficient offenses, as the result of better point guard play, since the introduction of the three point basket.

The Nets will probably lose Deron Williams, their star point guard, if they do not attract Dwight Howard to Brooklyn.  Another outstanding Eastern Conference point guard, Rajon Rondo, has been the subject of trade rumors since the lockout ended.  The East/West imbalance in point guard play will be exacerbated if Williams or Rondo moves to a team in the West.   But if Jeremy Lin continues on the pace he established in the past five games, the East will begin to narrow an offensive efficiency gap that has lasted for years.

%d bloggers like this: